Unitary wood chipping disk with removable knife assembly and independent wear plate



c. L. DURKEE 2,712,904 UNITARY WOOD CHIPPING DISK WITH REMOVABLE KNIFE ASSEMBLY AND INDEPENDENT WEAR PLATE 2 Sheets-Sheet l INVENTOR.

July 12, 1955 Filed Nov. 28. 1952 DURKEE UNITARY WOOD CHIPPING DISK WITH REMOVABLE KNIFE ASSEMBLY AND INDEPENDENT WEAR PLATE Filed Nov. 28, 1952 2 Sheets-s 2 VENTOR,

United States Patent 6 EJNKTARY WQOD cmrrmo DESK WITH REMOV- ABLE KNIFE ASSEMBLY AND INDEPENDENT WEAR PLATE Clarence L. Durkee, Wausau, Wis, assignor to l). J.

Murray Manufacturing Co., Wausau, Wis, a corporation of Wisconsin Application November 28, 1952, Serial No. 322,980

2 Claims. (Cl. 24192) having a series of revolving knives carried by a rapidly rotatable disk and cooperating with wood logs delivered through an inclined spout into the path of revolution of the knives.

The primary object of the present invention is to provide a rotary wood chipper of the above general type,

which is simple and durable in construction and highly efiicient in operation.

As shown in the Payzer Patent No. 1,906,486 granted May 2, 1933, it as long been customary to reduce wood logs and slabs into chips for the production of paper pulp, with the aid of a rotary chipper having an annular series of radial knife assemblages mounted in cavities or recesses in a heavy solid disk rapidly rotatable about a horizontal axis, and cooperating with the elliptical discharge opening of an inclined feed spout and with a flat bed knife disposed tangent to the bottom of the elliptical spout outlet and which coacts with the revolving knives to sever the logs sliding downwardly within the spout into successive chips. While this type of chipping unit was generally satisfactory, it was very costly to manufacture the rotors due to the confinement of the knife assemblages within cavities which had to be formed by tedious machining operations within solid heavy steel disks of large diameter and great thickness, and it also resulted in the production of objectionable slivers and other waste because the revolving lmife edges did not properly cooperate with the log and slab ends and with the fixed bed knife so as to insure clean cutting of the wood as these revolving edges left the cut.

It is therefore an important object of my invention to provide an improved rotary chipper which obviates the above mentioned objectionable features and which will msure the production of uniform chips devoid of excessive slivers and other waste materials.

Another important object of this invention is to provide an improved mounting for the revolving knives of a rotary chipper whereby excessive recessing and other difficult machining of the rotary knife carrying disk is avoided while proper coaction of the portion of the rotor between the successive revolving knives with the spout outlet is still maintained.

A further important object of the present invention is to provide an improved feed spout and bed knife assemblage for rotary wood chippers, wherein the logs are guided along a V-shaped spout bottom, having a V-shaped bed knife associated with its lower delivery end and cooperating with the revolving knife edges so as to produce clean shearing or cutting along the extreme lower edge portions of the logs.

Still another important object of my invention is to provide various improvements in the construction of rotary chippers whereby the various parts may be readily rotor the cutting adjusted and replaced with minimum efiort and at mod erate cost, and which result in a sturdy and durable unit having maximum capacity adapted to effectively reduce logs of diverse diameters and shapes.

These and other objects and advantages of this invention will be apparent from the following description from which it will be noted that the gist of the improvement is the provision of a wood chipper having a unitary rotary disk provided with a plane side surface and an annular series of chip delivery openings extending therethrough away from the plane surface, a revolvable knife assembly secured to the plane disk surface adjacent to each of the openings and each being separated from the succeeding knife by means of a sector shaped plate having a plane outer surface disposed parallel to said disk surface and providing a substantially continuous annular plane surface lying closely adjacent to the annular path oftravel of the knife edges, and an inclined feed spout having a V-shaped guiding bottom for the logs and provided with a similarly shaped bed knif e the inner edge of which is substantially parallel to the advancing knife edges as they leave the out while the outer bed knife edges are substantially perpendicular to the advancing cutting edges.

A clear conception of the features constituting my present improvements and of the construction and operation of a typical rotary wood chipper embodying the invention, may be had by referring to the drawings accompanying and forming a part of this specification wherein like reference characters designate the same or similar parts in the various views.

Fig. 1 is a rear view of one of the improved log feeding spouts of the typical wood chipping unit, showing the some cooperating with a fragment of a ten knife chipping knife edges of which are shown in heavy dash lines;

Fig. 2 is a part sectional side elevation of the feed spout and rotor fragment shown in Fig. l, the section through the spout having been taken along the line 22;

Fig. 3, is a fragmentary side view of the improved chipper rotor looking toward the revolving knives and the intervening spacer plates;

Fig. 4 is an enlarged section through the knife carrying rotor of Fig. 3, taken along the irregular line 44;

Fig. 5 is a fragmentary section through the rotor disk of Fig. 3, taken along the line 5-5 and showing the manner in which the unitary blade carrying disk is attached to its driving shaft; and

Fig. 6 is a fragmentary section through the same disk and one of the knife spacer plate assemblages, taken along the line 6-6 of Fig. 3.

While the invention has been shown and described herein as having been embodied in a ten knife chipper having a carrying disk of relatively large diameter, it is not the intent to unnecessarily restrict the improved features by virtue of this limited showing; and it is also contemplated that specific descriptive terms employed herein be given the broadest possible interpretation consistent with the disclosure.

Referring to the drawings, the improved rotary wood chipping unit shown comprises in general a unitary rotary disk 8 mounted upon a driving shaft 9 and having a plane side surface it radial chip delivery openings lit extending through the disk 8 away from the surface it a revolvable fiat elongated knife blade 12 disposed at an oblique angle relative to the disk surface 10 adjacent to each through opening 11 and each being firmly secured to the disk 8 and having a sharp cutting edge 13 extending tangent to a circle coaxial of the axis of the shaft 9 and all of which edges 13 are revolvable in a common plane parallel to the disk surface 1%; a composite sector shaped and an annular series of elongated heavy 3 spacer plate each consisting of an inner anchoring plate 14 and an outer wear plate 15, firmly secured to the disk 8 between each pair of successive knives 12, and all having outer plane surfaces 16 disposed closely adjacent to the plane of travel of the knife edges 13; an inclined log feed spout 17 having a lower stationary section 18 provided with a l -shaped bottom 19 secured to a sturdy frame 20, and also having'a semi-circular top section 21 swingably secured to the lower section 18 by means of pivoted links and a ti-shaped bed knife 23 secured to an adjusting block 24 slidably mounted upon the frame Ztl, the bed knife having relatively angularly disposed cutting edges 25, 26 located closely adjacent to the plane of cutting of the revolvable knife edges 13.

The unitary disk 8 should be of sturdy and relatively construction in order to provide sufiicient inertia or fly wheel effect to cause the knives 12 to travel smoothly through the cut, andthe opposite plane surfaces and the peripheral surface of this disk 8 may be conveniently and accurately machined with standard turn ing machines, while the chip delivery openings. ll may be drilled and broached as will be apparent from Fig. 3. The disk 8 is firmly attached to a flange on the driving shaft 9, by means of an annular series of bolts 28 as illustrated in Figs. 3 and 5, and normally need not be removed for replacement, but the trailing surfaces of each of the openings 11 is provided with a wear resisting liner 29 held in place along its chamfered outer edge by a wedge shaped blade reaction block 250 having a similarly chamfered overlapping edge, and at its opposite edge by one or more screws 31 as shown in Fig. 4, thus providing smooth wearing. surfaces along the trailing sides of the openings 11. The outer plane face of the disk 8 which is bounded by the surface 10 is provided with a series of sturdy lugs 32 welded or otherwise firmly attached thereto, and with a like series of radial slots 33 disposed between the successive lugs 32 and in each of which a radial key 34 is confined.

Each of the revolvable knife assemblages besides including a knife blade 12 and a reaction block 30, also comprises a knife seat 36 and a retainer plate 37 both serving to clamp the blade in position and being firmly secured to the disk surface 19 by bolts 38 which penetrate the disk 8 and additionally hold the liners 29 in 7 place. The bolts 33 are normally locked against turning by strips 39 coacting with flat portions on the bolt heads, and each knife blade 12 has its inner portion slotted to clear the bolts 38 and is adjustable outwardly by shims or jack screws 40 coacting with its inner edge and with the seat 36 as illustrated in Fig. 4. The lugs 32 carried by the disk 8 are of sufficient height so as to engage the outer ends of the adjacent seat 36 and retainer plate 37 of the adjoining knife assembly in order to absorb the centrifugal force acting upon the latter, and the outer surfaces of the retainer plates 37 are slightly inclined away from the plane of cutting of the knife edges 13 and toward the plane outer surfaces 16 of the adjacent sector wear plates 15. The inner sector plates 14 are grooved for snug coaction with the keys 34 and are clamped thereto by screws 41, while the outer and inner sector plates 15, 14 are additionally secured to the disk 8 by numerous bolts 42 which penetrate the rotor disk, see Figs. 3 and 4. t

The improved spout assemblage 17 which feeds the elongated logs 44 shown in dot-and-dash lines in Fig. l, by gravity toward the plane of cutting of the revolving knife edges 13, along the J-shaped bottom 19 of the lower spout section 13, is also of durable construction and is normally fixed but is adjustably secured to the main frame 20 by means of wedge blocks 45 and bolts 46, as illustrated in Fig. l. The upper spout section 21 which is connected to the lower section 18 by the pivoted links 22 is also normally fixed, but is adapted to lift or swing upwardly in case of a chokeup within the spout 17; and the bed knife 23 which is detachably secured xix to the anvil block 2 is formed of two similar but reversely inclined parts each having one of the cutting edges 25, 26 formed thereon. The bed knife edge 25 which is nearest to the shaft 9, is inclined so that the successive knife edges 13 are approximately parallel thereto when these edges finish a cut, and the other bed knife edge 26 is substantiall perpendicular to the inner edge 25 at the discharge opening of the spout 17. The bed knife adjusting anvil or block 24 which is slidably supported upon the frame 20 and is clamped in place between the frame elements by the bolts 46, is adjustable by means of screws 47 and nuts 4% coacting with a fixed cross-beam 49, and has a V-shaped cut-out 5t therein disposed in substantial alinement with the V- shaped bottom 19 of the spout section 18 and this cutout is preferably lined with wear resistant material. The block 24- and the bed knife 23 may be adjusted to bring the knife edges 25, 2-6 in proper coaction with the revolving knife edges 13 by manipulating the nuts 43 upon the screws 47, and the block 24 may thereafter be locked in adjusted position with the aid of a clamping cap screw 51 against 5 ms 52, see Figs; 1 and 2.

When the various parts of the improved rotary wood chipping unit have been properly constructed and assembled, the revolvable knives 12 and the bed knife 23 should be properly adjusted while the machine is idle,

to cause the knife edges 13 to revolve in a plane perpen dlcular to the axis of the shaft 9 and to clear the bed knife edges 25, 26 with minimum clearance. The knives 12 may be properly positioned with the aid of backing shims or the jack screws 4% within the spaces between the seats 36 and the retainer plates 37 while thebolts are released, and the bed knife 23 may be adjusted with the aid of the screws s7 and nuts 48 while the cap crew 51 is released. Proper positioning of the knives i2 is important since it determines the chip length and thickness. The disk 8 may then be rotated at high speed by applying power from any suitable source to the driving shaft 9, whereupon the knives 12 will be rapidly revolved past the lower spout outlet opening andpast the fixed bed knife 23, as indicated by the arrows in Figs. 1 to 4 inclusive.

Successive logs 44 of diverse cross-sectional shapes and diameters may then be admitted to the upper open end of the spout 17 and permitted to gravitate along the ti-shaped spout bottom 19 toward the chipping zone, and this V-shaped spout formation provides a support hich positively prevents the logs from bouncing. As the lower ends of the logs 44 enter the path of the revolving knife edges 13, these log ends are cut into chips which are rapidly delivered through the openings 11 in the disk 8 and are thrown clear of the rotor. When out, each blade edge 13 takes a shearing cut across the outer bed knife edge 26 and assumes a position approximately parallel to the bed knife edge 25 as it leaves the cut, thereby causing each knife edge 13 to leave the cut at the point of contact of the log with the spout and insuring the production of clean chips practically devoid of sawdust and slivers. The annular plane surface 16 formed by the sector plates 16 prevents the logs 44 from tilting and advancing too far toward the rotor between succes- Eve cuts while providing desirable clearance just beyond each edge 13, and if the spout 17 becomes. clogged the links 22 will act quickly to permit the upper spout section 21 to rise and thus relieve the choke-up.

The knife edges 13 should be maintained in sharp xsndition dressed to minimum angles in order to insure e knife blades 12 approach the lowermost end of each against practically all wear it will last indefinitely by merely replacing the liners 29 from time to time. The ugs 32 and the keys 34 cooperate with the bolts 38, 42 and with the screws 41 to firmly retain the knife and sector plate assemblies upon the rapidly revolving flywheel disk 8 and to thus produce a durable rotor structure.

From the foregoing detailed description it will be apparent that the present improvements provide a rotary wood chipper in which all parts may be readily constructed, assembled, and adjusted to effectively produce uniform and clean chips in rapid succession. The simplified mounting of the revolvable knives 12 provides a divided rotor and not only facilitates construction of the disk 8 and renewal of worn relatively inexpensive parts, but also cooperates with the improved V-shaped bed knite 23 so as to produce most efficient cutting action on the logs 4-4. The V-shaped formation of the bed knife 23 with its relatively inclined edges 25, 25 cooperating with the revolving knife edges 13 in the manner hereinabove described, is of utmost importance in eliminating formation of slivers, sawdust and other waste material when cutting logs of various diameters by avoiding bouncing of the logs, and the several improvements have proved highly satisfactory and successful in actual commercial use.

it should be understood that it is not desired to limit this invention to the exact details of construction and operation of the ten knife rotary chipping unit, herein specifically shown and described, for various modifications within the scope of the appended claims may occur to persons skilled in the art.

I claim:

1. A wood chipping rotor comprising, a unitary rotary disk having a plane annular side surface disposed perpendicular to the axis of rotation of the disk and which is interrupted by an annular series of elongated approximately radial chip delivery openings extending through the disk away from said surface and by an annular series of outwardly projecting rigid lugs disposed between the outer ends of the successive openings, an elongated knife assembly detachably secured to said disk surface directly behind each of said openings and having its outer end coacting with an adjacent lug to oppose the action of centrifugal force upon the knife assemblies, and an independent sector shaped wear plate also detachably secured to said disk surface and filling the space between each knife assembly and the next succeeding chip delivery opening to oppose the cutting pressure acting upon the knife assemblies.

2. A wood chipping rotor comprising, a unitary rotary disk having a plane annular side surface disposed perpendicular to the axis of rotation of the disk and which is interrupted by an annular series of elongated approximately radial chip delivery openings extending through the disk away from said surface and by independent annular series of outwardly projecting approximately radial keys and local lugs disposed between the successive openings, an elongated knife assembly detachably secured to said disk surface directly behind each of said openings and having its outer end coacting with an adjacent lug to oppose the action of centrifugal force upon the knife assemblies, an independent sector shaped anchoring plate coacting with each of said keys and directly with said disk surface and filling the space between each knife assembly and the next succeeding chip delivery opening to oppose the cutting pressure acting upon the knife assemblies, and a sector shaped Wear plate detachably secured to each of said anchoring plates and coacting with the rear of an adjacent knife assembly.

References Cited in the file of this patent UNETED STATES PATENTS 775,382 Philbrick Nov. 22, 1904 1,942,675 Wigger Jan. 9, 1934 2,299,248 Ottersiand Oct. 20, 1942 2,570,845 Otterland Oct. 9, 1951 

